Space Cake

Hello Space Cake!

The new all-road bike from Sour is designed to take you further, faster.

The Space Cake can take you anywhere the roads go—“road,” of course, being more of a theory than a rule..

For the last five years, we’ve had this itch that something was missing. Deep in the back of our minds, we knew that a road-plus bike—something fast and efficient but still built to get weird when the road turns rough—would be the perfect addition to our lineup. It took time to nail down the right geometry, tubing, and design details to create a bike that stayed true to Sour’s adventurous spirit.

Now, after countless prototypes and test rides, the Space Cake is here: a road bike that blends speed with the durability to tackle all roads, whether they’re paved, or “paved”.

Roads are just a suggestion

The Space Cake may be the most “road” bike we’ve ever made, but don’t be fooled—it’s still got a bit of that playful spirit Sour is known for. With geometry that’s tuned for long road days but a durability that says ‘bring on the rough stuff,’ it’s made for for when that perfect stretch of asphalt turns into an irresistible gravel path. Ride farther, ride faster, and don’t be afraid to get a little adventurous.

Road bikes a lot different than they used to be. Gone are the days of skinny tires! In an era where usability reigns supreme, the Space Cake is king. We designed this bike to do go farther than you thought you could, and carry you back home too.

The Ultimate All-Road Weapon

This is Sour’s take on a road bike—light, responsive, and built for speed, but not afraid to ignore the rules. It’s for the roadies who like to get a little weird, the MTB riders looking for a fast training machine, and anyone who sees a gravel detour as an opportunity, not an obstacle. So, go ahead: hit the smooth stuff, seek out the rough patches, and leave the route up to your imagination.

It’s been a long time coming, building an all-road bike. No joke, it’s been in the planning hopper for more than three years at this point. All that goes to say that when we finally made the step, went “full-roadie”, we really wanted to do it right, and do it our way!

Looks fast, goes anywhere.

Why choose between speed and style? Like every Sour model, the Space Cake comes with our signature custom powder coating, so your bike can turn heads on the tarmac or the occasional gravel detour. Bold, classy, or a little offbeat—it’s up to you. After all, just because you’re chasing KOMs doesn’t mean you can’t look good doing it.

Don’t lie, going fast is really, really fun. While going fast is sometimes also really, really hard, the Space Cake makes it as easy as possible. We designed tubing and frame parts to be as light and efficient as possible. Plus, you’ll be able to full-send every bit of gravel on the weekly group ride, so you can always close that gap if you need to!

Made to Go the Distance

Designed with endurance in mind, the Space Cake is all about going longer and pushing your limits. With a road-focused frame built to handle big miles, it’s comfortable, light, and efficient enough to keep you smiling through epic rides. Whether you’re leading the pack on a group ride or setting out solo for some solid-state training, this bike is here for the long haul.

We love mountain biking, it’s at the core of our DNA, but just as any well-adjusted mountain biker will tell you, a touch of endurance never hurt your berm-slashing game. All-road bikes and gravel bikes are at the heart of our off-MTB-season riding – filling in the gaps between wet and dry season, fitness gaps, or just the gap between your house and the office!


Shop the Space Cake in our online store!


Geometry

Specification

All Sour Bicycles frames are made by hand, one-by-one, in our own facility in Saxony, just outside of Dresden. We use custom tubing designed and drawn for our frames, it’s a multi-butted heat-treated 4130 CrMo steel that’s ready to stand the test of time. All our steel is produced from a partially recycled product in Germany and drawn by one of the worlds leading production facilities in Taiwan, the beating heart of the worlds bicycle production.

Our dropouts are designed in-house in Dresden and have a replaceable derailleur hanger.

The seat clamp is designed in-house and is integrated into the frame. Should it ever fail, the frame can be professionally modified to use a traditional clamp, if repair of the original clamp is not possible. We have never seen one fail.

By The Numbers

Headtube: 44 mm upper and lower
Bottom bracket: External 68mm T47 threaded bottom bracket
Axle: 12mm x 142mm thru axle
Seat post: 27.2mm
Brake standard: FM160 Direct. More info here.
Wheel size: Size S-XL 700C
Tire clearance: up to 38mm
Tubing: Custom drawn, multiple butted, partly heat treated SOUR CrMo (we love steel)

Bonus facts and features:

Fender and rack mounts
Recommended tire size 28mm – 38mm
Two water bottle mounts inside frame, a third bottle mount under the downtube
AXS/Di2 ready cable routing
Internal brake hose routing
External mechanical cable routing
27,2mm seatpost diameter for maximum comfort
SRAM Transmission compatible dropouts (“UDH”)

Space Cake Fork

The perfect fork to pair with a pack-light-travel-fast Sour Space Cake build. We love the versatility of our Space Cake frames, and this fork is just the cherry on top. Ready for those extra long rides, but minimal enough for all the day-to-day grind. Perfect..

Specs

Maximum Tire Width: 38mm
Axle to Crown Length: 389mm
Rake: 45
Tapered Steerer Tube 1 ½“ –  1 ⅛“
Thru-axle 12mm x 100mm
Material UD Carbon


Flat-mount Brake Mount 140/160mm
Fender Mounting Possible
Hub Dynamo Cable routing
Weight With Full Steerer and Axle: ±515g

Below are the frame and fork weights for each size of the Sour Space Cake. These weights include powdercoating, but please keep in mind that your chosen powdercoat may be heavier than the average coating we use. Fades, gradients, and metallic colors can weigh more than single solid color powdercoat. If you are interested the final weight, please get in touch. Weights are averaged over three frames per size. We apply an inside wax coating before shipping the frame to your door that will add additional weight.


Size S = 1925g
Size M = 1985g
Size L = 2050g
Size XL = 2150g

All-Road Carbon fork = 515g

*All weights averaged with 3 frames per size (±50g frame, ±20g fork)

Included with your frame

Included with your Space Cake frame or frameset is all the grommets and small parts to run any cabling you wish and a derailleur hanger. You get a rear thru-axle of course, and if you’re ordering a frameset, you get a front axle with your fork as well. Headsets are only included if you add one to your order.

2×12 Shimano Ultegra R8100 Di2

Rear Derailleur, Shimano Ultegra Di2 RD-R8150
Front Derailleur, Shimano Di2 FD-R8150
Crankset, Shimano Ultegra FC-R8100, 172,5mm with 50/35t chainrings 
Shifters, Shimano Ultegra Di2 ST-R8170+BR-R8170 with RT-CL800S 160mm Discs
Cassette, Shimano ULTEGRA CS-R8101 11-30t with CN-M7100 chain

Parts

Wheelse,t built by hand with Duke Baccara RX 42 SLR2 rims paired with Duke Bad Boy J-Bend, Centerlock hubs. 28h, Sapim bladed spokes.

Complete Easton EA90 cockpit:
S — 90mm stem; handlebar 400mm 16° flare; seat post 27,2x350mm; Easton bartape
M-L — 100mm stem; handlebar 420mm 16° flare; seat post 27,2x350mm; Easton bartape
XL — 110mm stem; handlebar 440mm 16° flare; seat post 27,2x350mm; Easton bartape

Saddle SQ Lab 611 Ergowave XS-L 140mm XL-XXL 150mm
White Industries Headset
White Industries Bottom Bracket

Tires, Schwalbe Pro One 700×34 tubeless

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